five-second rule

five-second rule (plural five-second rules)

1. Any rule that allows or prohibits certain behavior for five seconds after some event, especially:
   1. (informal) The belief that food dropped on the ground is still hygienic to eat provided it is picked up within five seconds of touching the ground.
      • 2007-05-09, Harold McGee, The New York Times, "The Five-Second Rule Explored, or How Dirty Is That Bologna?", page F3

        Accompanied by six graphs, two tables and equations whose terms include “bologna” and “carpet,” it’s a thorough microbiological study of the five-second rule: the idea that if you pick up a dropped piece of food before you can count to five, it’s O.K. to eat it.

      • 2010, Sandy Donovan, Does an Apple a Day Keep the Doctor Away?‎:

        UNFORTUNATELY, THE FIVE-SECOND RULE IS A MYTH.

      • 2012, William A. Dando, Food and Famine in the 21st Century, page 201:

        Here are five facts to remember for those who are tempted to apply the five-second rule.

      • 2015, Curious George Discovers Germs‎:

        Often, people call out the five-second rule because they think that if you get food off the floor quickly enough, there won't be any germs on it.

   2. (basketball) A rule that a closely-guarded player cannot hold the ball for more than five seconds without dribbling, passing, rolling, or shooting the ball.
   3. (basketball) A rule that a player who throws in the ball from out of bounds must get rid of it in less than five seconds.

• two-second rule
• three-second rule
• ten-second rule